Electronic device on user equipment side in wireless communication system and wireless communication method

ABSTRACT

An electronic device on a user equipment side in a wireless communication system and a wireless communication method. The electronic device includes: a communication unit, configured to implement device-to-device (D2D) communication under a cellular communication protocol with multiple user equipments, to directly send data and/or control information to the multiple user equipments; and a configuration unit, configured to configure, for a first user equipment and a second user equipment in the multiple user equipments, resources and a modulation and coding scheme (MCS) for implementing D2D communication between the first user equipment and the second user equipment, wherein the second user equipment is a candidate that the first user equipment implements D2D communication with, and the communication unit send information indicating the resources and the MCS to the first user equipment and the second user equipment.

FIELD

The present disclosure relates to the field of wireless communicationtechnology, and particularly to an electronic device on a user equipmentside in a wireless communication system and a wireless communicationmethod in the wireless communication system.

BACKGROUND

This part provides background information related to the presentdisclosure, and it is not necessary to be the prior art.

The D2D (Device-to-Device) communication technology refers to aninformation transmission way, in which, a cellular communication UE(User Equipment) performs data interaction directly in a way of terminaldirect connection. Compared with traditional cellular communication, inthe D2D communication, a spectrum resource is reused, a transmissiondistance is short and information is not relayed through a base station,therefore the D2D communication can increase a spectrum utilizationratio, decrease a transmission power of the UE and load of the basestation. In a case that a DUE (Device-to-Device User Equipment) which isperforming the D2D communication is to switch from a D2D communicationmode to a traditional cellular communication mode, design for a switchflow and an involved signaling is a part not involved in currentstandard work. However, since that the switch from the D2D communicationmode to the traditional cellular communication mode is different from atraditional switch mechanism of the UE from a base station to anotherbase station, and reflects that a communication target of the UE isswitched from a UE to a base station, that is, from a nontraditionalcommunication mode to a traditional communication mode, the switch flowin this mechanism needs to be planed and designed according a particularscenario, thereby ensuring rationality and reliability of the switchflow while reducing signaling overhead to the greatest extend.

In addition, D2D broadcasting is an important concern of the current3GPP (3rd Generation Partnership Project) RAN1 (Radio Access Network),and is mainly applied to the field of public safety. The D2Dbroadcasting is point to multiple points communication, a source DUE isa broadcasting source UE for providing a broadcasting service, and thesource DUE provides same information to the remaining DUEs, and does notreceive feedback information from the UE. Due to a particular factor,the D2D communication is switched to other mode from the broadcastingmode in a case that quality of a D2D broadcasting link gets worse andcan not meet a service requirement of a receiving DUE, to ensurecompleteness of receiving the information. However, a specific flow andscheme for switching the D2D communication from the broadcasting mode tothe other mode is not discussed in the conventional technology, forexample, which entity and how to trigger the mode switch without thefeedback information. In some known study, a UE cluster is constructedin a case that multiple DUEs which meet a certain distance conditionhave a communication requirement. An advantage of the D2D communicationcluster is centralized control, that is, the base station maintainstraditional links with only a few UEs in the cluster, this is equivalentto that all UEs in the cluster maintains traditional links with the basestation. One DUE in the DUE cluster is set as a cluster head, thecluster head maintains a traditional link with the base station, and isresponsible for forwarding information from the base station. A nodeexcept the cluster head in the DUE cluster is referred to as a slaveDUE. The slave DUE does not have a connection link with the cellularbase station, or performs limited communication with the cellular basestation, for example, the slave DUE is in a LTE-DETACHED state. Comparedwith a case that all UEs maintain the link connection with the basestation, an interaction signaling is decreased greatly in a case thatthe slave DUE is not connected to the base station or performs thelimited communication with the base station. The communication mode isnot only suitable for a future communication scenario of high speed anddense cell deployment, but also suitable for a scenario of the field ofpublic safety. However, a specific function of the cluster head and anoperation required in the D2D communication and a correspondingoperation of the slave DUE needs to be further planed and designed.

SUMMARY

This part provides a general overview of the present disclosure, and isnot overall disclosure for a full scope or all features of the presentdisclosure.

An objective of the present disclosure is to provide an electronicdevice on a user equipment side in a wireless communication system and awireless communication method in the wireless communication system, tomake clear and enhance an assisting role of a cluster head and thereforesolve at least one of the technical problems mentioned above.

An electronic device on a user equipment side in a wirelesscommunication system is provided according to an aspect of the presentdisclosure, the electronic device includes circuitry configured toperform device-to-device D2D communication under a cellularcommunication protocol with multiple user equipments, to directlytransmit data information and/or control information with the multipleuser equipments; and configure, for a first user equipment and a seconduser equipment of the multiple user equipments, resources and aModulation and Coding Scheme MCS for performing the D2D communicationbetween the first user equipment and the second user equipment, thesecond user equipment being a candidate object with which the first userequipment performs the D2D communication, where the communication unittransmits information indicating the resources and the MCS to the firstuser equipment and the second user equipment.

An electronic device on a user equipment side in a wirelesscommunication system is provided according to another aspect of thepresent disclosure, the electronic device includes circuitry configuredto receive information indicating resources and a Modulation and CodingScheme MCS for performing D2D communication under a cellularcommunication protocol between the electronic device and a second userequipment from a first user equipment; and modulate and code data to betransmitted based on the MCS information, where the communication unitfurther transmits the modulated and coded data to be transmitted to thesecond user equipment through the resources, to perform the D2Dcommunication.

An electronic device on a user equipment side in a wirelesscommunication system is provided according to another aspect of thepresent disclosure, the electronic device includes circuitry configuredto measure a base station equipment included in a potential cell list;and predict a target base station equipment for a user equipment in auser equipment cluster which performs device-to-device D2D communicationbased on a measurement result.

A wireless communication method in a wireless communication system isprovided according to another aspect of the present disclosure, thewireless communication method includes: performing, by an electronicdevice on a user equipment side in the wireless communication system,device-to-device D2D communication under a cellular communicationprotocol with multiple user equipments, to directly transmit datainformation and/or control information with the multiple userequipments; configuring, for a first user equipment and a second userequipment of the multiple user equipments, resources and a Modulationand Coding Scheme MCS for performing the D2D communication between thefirst user equipment and the second user equipment, the second userequipment being a candidate object with which the first user equipmentperforms the D2D communication, where information indicating theresources and the MCS is transmitted to the first user equipment and thesecond user equipment.

A wireless communication method in a wireless communication system isprovided according to another aspect of the present disclosure, thewireless communication method includes: receiving from a first userequipment, by an electronic device on a user equipment side in thewireless communication system, information indicating resources and aModulation and Coding Scheme MCS for performing D2D communication undera cellular communication protocol between the electronic device and asecond user equipment; modulating and coding data to be transmittedbased on the MCS information; and transmitting the modulated and codeddata to be transmitted to the second user equipment through theresources, to perform the D2D communication.

A wireless communication method in a wireless communication system isprovided according to another aspect of the present disclosure, thewireless communication method includes: measuring, by an electronicdevice on a user equipment side in the wireless communication system, abase station equipment included in a potential cell list; and predictinga target base station equipment for a user equipment in a user equipmentcluster which performs device-to-device D2D communication based on ameasurement result.

The electronic device on the user equipment in the wirelesscommunication system and the wireless communication method in thewireless communication system according to the present disclosure makeclear and enhance the assisting role of a cluster head. In someparticular scenarios, for example, for a slave DUE which does not have aLTE (Long Term Evolution) link with a traditional cellular network in aprocess of D2D communication, the assisting role of the cluster head canimprove a switch speed and reduce signaling overhead in a case that theslave DUE is switched to a traditional cellular communication mode froma D2D communication mode. In addition, for example in a D2D broadcastingor multicasting communication scenario, the assisting role of thecluster head can assist a switch flow from the D2D broadcasting ormulticasting mode to a unicasting communication mode.

A further applicability region becomes obvious from a descriptionprovided here. The description for the overview and a particular exampleare only schematic, and are not intended to limit the scope of thepresent disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described here only schematically show the selectedembodiments instead of all possible embodiments, and are not intended tolimit the scope of the present disclosure.

FIG. 1 is a schematic diagram for showing a scenario of switching from aD2D broadcasting mode to a D2D unicasting mode according to anembodiment of the present disclosure;

FIG. 2 is a block diagram for showing a structure of a user equipmentaccording to an embodiment of the present disclosure;

FIG. 3 is a block diagram for showing a structure of a user equipmentaccording to another embodiment of the present disclosure;

FIG. 4 is a sequence diagram for showing a method for performingcommunication mode switch in a wireless communication system accordingto an embodiment of the present disclosure;

FIG. 5 is a sequence diagram for showing a method for performingcommunication mode switch in a wireless communication system accordingto another embodiment of the present disclosure;

FIG. 6 is a schematic diagram for showing a switch scenario from a D2Dcommunication mode to a cellular communication mode known by theinventor;

FIG. 7 is a block diagram for showing a structure of a user equipmentaccording to another embodiment of the present disclosure;

FIG. 8 is a sequence diagram for showing a method for performingcommunication mode switch in a wireless communication system accordingto another embodiment of the present disclosure; and

FIG. 9 is a block diagram of an exemplified structure of ageneral-purpose personnel computer for realizing a method for performingcommunication mode switch in a wireless communication system accordingto an embodiment of the present disclosure.

Although it is easy to make various modifications and substitutions ontothe present disclosure, particular embodiments, as an example, have beenshown in the drawings, and are described in detail here. However, itshould be understood that a description for the particular embodimentsis not intended to limit the present disclosure within a disclosed way,an objective of the present disclosure is to include all modifications,equivalents and substitutions within the principle and scope of thepresent disclosure. It should be noted that a label indicates acomponent corresponding to the label through the drawings.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An example of the present disclosure is described fully now withreference to the drawings. The description below is only exemplarysubstantially, and is not intended to limit the present disclosure, anapplication or a purpose.

Exemplary embodiments are provided to fully detail the presentdisclosure and convey the scope of the present disclosure to thoseskilled in the art. Several particular details such as an example of aparticular component, device and method are described, to fullyunderstand the embodiments of the present disclosure. It is clear forthose skilled in the art that, the exemplary embodiments can beimplemented in multiple different ways without using particular details,and the exemplary embodiments are not intended to limit the scope of thepresent disclosure. A well-known process, a well-known structure and awell-known technology are not described in detail in some exemplaryembodiments.

The present disclosure relates to D2D (Device-to-Device) communicationin the wireless communication network. A UE (User Equipment) in thepresent disclosure includes but not limited to a terminal, having afunction of wireless communication, such as a mobile terminal, acomputer or an on-board device. In addition, the UE in the presentdisclosure may also be the UE itself or a component such as a chip inthe UE. Furthermore, a base station in the present disclosure may forexample be an eNodeB or a component such as a chip in the eNodeB.

FIG. 1 shows a scenario of switching from a D2D broadcasting mode to aD2D unicasting mode according to an embodiment of the presentdisclosure.

As shown in FIG. 1, in a D2D broadcasting group, a source DUE (D2D UserEquipment) broadcasts information to other DUEs (i.e. DUE1, DUE2 andDUE3). In a case that a broadcasting link of DUE2 gets worse (forexample, DUE2 moves to a position far away from the source DUE) andtherefore information transmission quality can not be ensured, DUE2 isrequired to be switched to other communication mode from a current D2Dbroadcasting mode. In a case that a DUE is switched to a traditionalcellular mode from the D2D broadcasting mode, a base communicationrequirement (the DUE can perform continuous communication with thesource DUE via the base station or the DUE can perform communicationwith other DUE close to the DUE via the base station) of the DUE can beensured. However, this switch process will result in large signalingoverhead. The inventor in the present disclosure considers that the basecommunication requirement can also be met in a case that DUE2 isswitched to a unicasting communication mode with other DUE from the D2Dbroadcasting mode. For example, in a case that DUE2 still needs toacquire broadcasting information transmitted by the source DUE, DUE2 canbe switched to perform unicasting communication with DUE1 which hasacquired the broadcasting information, so as to receive the broadcastinginformation. Alternatively, in a case that a high-layer application ofDUE2 no longer concerns the broadcasting information, DUE2 can beswitched to perform unicasting communication with other DUE such as DUE4purposefully. A switch time and a signaling are decreased quite muchcompared with a case of switching to the traditional cellular mode.

In a scenario shown in FIG. 1, DUE1, DUE2, DUE4 and DUE5 are constructedinto a DUE cluster. In the DUE cluster, DUE5 is a CH (Cluster Head). Thecluster head in the present disclosure is a DUE within the cluster whichmaintains a link with a network side, and can assist members in thecluster in performing D2D communication mode switch.

There is a broadcasting source DUE in FIG. 1, which is a DUE fortransmitting a broadcasting message in D2D broadcasting communication.Other DUEs such as DUE1, DUE2 and DUE3 are DUEs for receiving thebroadcasting message in the D2D broadcasting communication. In addition,DUE such as DUE4 shown in (b) of FIG. 1 may be referred to as a newtarget DUE, which is a communication object with which DUE such as DUE2establishes D2D unicasting communication.

The scenario in FIG. 1 is only exemplary, and the present disclosure isnot limited thereto. For example, the source DUE and the cluster headmay be a same UE. In addition, the scenario in FIG. 1 may furtherinclude a base station such as an eNB (evolution Node Base Station) (notshown), the base station is a service cell where the DUE (for example,DUE2) and the cluster head are located, may be a service cell of the newtarget DUE, or may not be the service cell of the new target DUE, thatis, the new target DUE may be located in an adjacent cell of the DUE(for example, DUE2).

According to the embodiment of the present disclosure, for a clusteruser such as DUE2 in a D2D broadcasting cluster which is performing D2Dbroadcasting communication, DUE2 can be switched to the D2D unicastingmode from the D2D broadcasting mode in a case that quality of a linkbetween DUE2 and the source DUE which is performing the D2D broadcastingcommunication changes, that is, the quality of the link is reduced, toensure completeness and continuousness of receiving the information.Meanwhile, since that the user in the broadcasting cluster receivesinformation from a same source DUE, the user in the broadcasting clusteracquires same information theoretically without considering a problemsuch as information loss. Therefore, target information which is desiredto be acquired by the user in the broadcasting cluster performingtransmission mode switch may be changed or may not be changed, that is,the user in the broadcasting cluster can be switched to performunicasting communication with any one user in the broadcasting cluster.

FIG. 2 shows a structure of a UE 200 according to an embodiment of thepresent disclosure. In the embodiment, UE 200 may be served as a clusterhead, such as DUE5 in FIG. 1. As shown in FIG. 2, UE 200 may include acommunication unit 210 and a configuration unit 220. UE 200 may berealized as a mobile terminal (such as a smart phone, a panel personalcomputer (PC), a notebook computer, a portable game terminal, aportable/dongle mobile router and a digital camera device) or anon-board terminal (such as a car navigation device). UE 200 can berealized as a terminal (also referred to as a machine-type-communication(MTC) terminal) which performs machine-to-machine (M2M) communication.In addition, UE 200 may be a wireless communication module (such as anintegrated circuit module including a single wafer) installed on eachterminal of the terminals described above.

According to an embodiment of the present disclosure, UE200 can includea processing circuitry. Further, the processing circuitry can includevarious independent functional units to perform various and differentfunctions and/or operations. It is described that these functional unitscan be physical entities or logical entities, and the units in differentappellations may be implemented by a same physical entity. Further,UE200 can include one processing circuitry, also can include multipleprocessing circuitries. In addition, UE200 can further include acommunication unit as a transceiver.

The communication unit 210 may perform D2D communication under acellular communication protocol with multiple UEs (for example, DUELDUE2 and DUE4 shown in FIG. 1), so as to directly transmit datainformation and/or control information to the multiple UEs. The cellularcommunication protocol may be for example LTE-A (Long Term Evolutionadvanced), LTE-U and so on, which is not limited in the presentdisclosure.

The configuration unit 220 may configure, for a first UE such as DUE2 inFIG. 1 and a second UE such as DUE 4 in FIG. 1 of the multiple UEs,resources and a MCS (Modulation and Coding Scheme) for performing D2Dcommunication between the DUE2 and DUE4. DUE4 is a candidate object withwhich DUE2 performs the D2D communication.

The communication unit 210 may transmit information indicating theresources and the MCS to DUE2 and DUE4.

It should be illustrated that, in a case that the D2D communication hasa default dedicated MCS in an example of the present disclosure, theconfiguration unit 220 may not configure the MCS.

Specifically, the indicated resources are for example physical resourceblocks (PRB), the MCS information is for example five-bit I_(MCS) (anMCS index value) having a value range from 0 to 31. Each I_(MCS)corresponds to a modulation mode (for example, QPSK, 16QAM, 64QAM), andthe modulation mode can also be represented by a modulation order.I_(MCS) may also correspond to a transport block size (TBS). Inaddition, I_(MCS) may also correspond to a redundancy version in someexamples. Specifically, correspondences between a MCS index value and amodulation order, between a MCS index value and a transport block sizeand between a MCS index value and a redundancy version may berepresented in a format of table and may be stored in a chip of the DUEin advance. In an specific example, the table of the correspondencesbetween a MCS index value for the D2D communication and a modulationorder, between a MCS index value for the D2D communication and atransport block size and between a MCS index value for the D2Dcommunication and a redundancy version is the same as a table for PUSCHdefined in the current standard. In another example, a value range ofthe MCS index value for the D2D communication is a subset of the valuerange from 0 to 31, for example, from 10 to 20, thereby reducingcomplexity of modulation and coding between DUEs.

It should also be illustrated that each of the units related in thespecification and the appended claims may be a physical entity or alogical entity, units having different names may be realized by a samephysical unit. For example, a first transmitting unit and a secondtransmitting unit mentioned subsequently in the specification may berealized by a same physical unit for example an antenna, a filter or amodulator-demodulator.

According to the embodiment of the present disclosure, UE 200 served asthe cluster head DUE5 may configure the resources (and optionally theMCS) for performing the D2D communication for DUE2 and DUE4 in thecluster, thereby assisting in successfully switching to a unicastingcommunication mode from a D2D broadcasting or multicasting mode, orfurther assisting in a switch flow of switching from a D2D unitcastingcommunication object to another D2D unitcasting communication object.

According to the embodiment of the present disclosure, the communicationunit 210 may further receive indication information indicating qualityof a link between DUE2 and DUE4 from DUE2, for example, a measurementresult obtained by measuring by DUE2. In another example, the clusterhead UE 200 may measure for DUE2, and acquire an index of quality of alink between DUE2 and other DUE such as DUE4. In a case that the qualityof the link indicated by the indication information meets apredetermined condition, the configuration unit 210 may configure theresources and the MCS for performing the D2D communication between DUE2and DUE4. In other words, the configuration unit 210 configures theresources and the MCS in consideration of the quality of the linkbetween DUE2 and DUE4, that is, quality of a channel and a radiocondition. In addition, the configuration unit 210 may consider theresources and the MCS configuration based on at least one of a QoSrequirement, a buffer status and an interference condition of a currentservice received from DUE2. In this way, the switch flow is performedsuccessfully.

For example, in a case that UE 200 served as the cluster head DUE5 islocated within a service scope of a base station, the communication unitcan transmit switch request information indicating that DUE2 is toperform D2D communication with DUE4 to the base station equipment, andreceive switch request acknowledge information from the base stationequipment. For example, UE 200 determines whether the quality of thelink between DUE2 and DUE4 meets the predetermined condition, and UE 200transmits switch request information to the base station equipment in acase that the quality of the link meets the predetermined condition, toreduce system overhead. Here, the switch request information may includeat least one of a QoS requirement, a buffer status and an interferencecondition of a current service of DUE2 received from DUE2, the switchrequest acknowledge information may include resource allocationinformation for the D2D communication between DUE2 and DUE4. In thiscase, the configuration unit 220 may configure the resources and the MCSat least based on the switch request acknowledge information. In anexample, UE 200 transmits a high-layer signaling such as a RRC messageincluding the switch request information to the base station equipment.Correspondingly, the base station equipment feedbacks a RRC messageincluding the resource allocation information for the D2D communicationbetween DUE2 and DUE4 to UE 200. UE 200 parses the RRC message in a highlayer to extract the resource allocation information for the D2Dcommunication between DUE2 and DUE4. Specifically, a scheduler in thebase station equipment determines resources allocation based on at leastone of the quality of the link between DUE2 and DUE4, the QoSrequirement of the service, the buffer status and the interferencecondition. As an example, the scheduler for the D2D communication isarranged in the base station equipment dedicatedly, to allocateresources to a D2D user in a semi-static way.

In another aspect, for example, in a case that UE 200 served as thecluster head DUE5 is located outside of the service scope of the basestation, the configuration unit 220 may select a resource from apredetermined D2D communication resource pool to configure.Specifically, in an example, the predetermined D2D communicationresource pool is information stored in advance in a chip of a userequipment which supports the D2D communication, for example, a resourcein a specific spectrum. In another example, in a case that UE 200 servedas the cluster head DUE5 is located within the service scope of the basestation, the predetermined D2D communication resource pool is specifiedby the base station equipment in advance, for example, the predeterminedD2D communication resource pool is specified through a RRC message, andUE 200 can update information in the resource pool by a RRC messagetransmitted by the base station again. In this example, UE 200 canallocate the resources for the D2D user without the assistance of thebase station equipment. In a case that the cluster head UE 200 alsoreceives a D2D communication requirement between other DUEs managed byUE 200, the configuration unit 220 operates as a scheduler, thescheduler operates for example in a RRC layer or a MAC layer, anddetermines a communication resource for the other DUEs based on at leastone of the quality of a link between the other DUEs, a QoS requirementof a service, a buffer status and an interference condition.

According to the embodiment of the present disclosure, the communicationunit 210 may further receive indication information indicating qualityof a link between DUE2 and a third UE such as the source DUE in FIG. 1from DUE2. Except that it is assumed that DUE2 is performing D2Dbroadcasting communication with the source DUE in advance, it is assumedthat DUE2 is performing D2D unitcasting communication with the third UEin advance, which is not limited in the present disclosure. In any case,the predetermined condition mentioned above may at least include thatthe quality of the link between DUE2 and DUE4 is better than the qualityof the link between DUE2 and the source DUE.

According to the embodiment of the present disclosure, the communicationunit 210 may also receive information indicating the source DUE is abroadcasting information source for DUE2 and DUE4 from DUE2 and/or DUE4.At this time, in a case that the predetermined condition is met, theconfiguration unit 220 may determine that DUE2 performs the unitcastingD2D communication with DUE4, so that DUE2 continues to acquirebroadcasting information from DUE4. Furthermore, the communication unit210 may receive a transmission frame number status (SN STATUS) betweenDUE2 and the source DUE from DUE2, and transmit the transmission framenumber status to DUE4, so that DUE2 continues to receive broadcastinginformation of the source DUE from DUE4.

According to the embodiment of the present disclosure, the configurationunit 220 may be further configured to configure HARQ (Hybrid AutomaticRepeat Request) for the D2D communication between DUE2 and DUE4.Specifically, the configuration unit 220 may for example configure aparameter such as a feedback frequency of HARQ, for example, it isdefined that feedback is performed once for n transport blocks, where nis an integer greater than 1. In addition, the communication unit 210may transmit HARQ configuration information to DUE2 and DUE4.

According to the embodiment of the present disclosure, the configurationunit 220 may further configure, for DUE2, D2D communication connectionassistance information for accessing into DUE4. The D2D communicationconnection assistance information may include for example a RA preamble(Random Access preamble), a D2D RACH (Random Access Channel) resourceand so on. Furthermore, the communication unit 210 may transmit the D2Dcommunication connection assistance information to DUE2.

According to the embodiment of the present disclosure, the communicationunit 210 may transmit information indicating the resources and the MCSto DUE2 and DUE4 through a RRC (Radio Resource Control) signaling.

The structure of UE 200 served as the cluster head DUE 5 is describedabove in conjunction with FIG. 2. A structure of a UE served as anordinary DUE within the cluster according to the embodiment of thepresent disclosure is described below. FIG. 3 shows a structure of UE300 served as an ordinary DUE such as DUE2 in FIG. 1 within the cluster.As shown in FIG. 3, UE 300 may at least include a communication unit 310and a control unit 320.

The communication unit 310 may receive information indicating resourcesand a MCU for performing D2D communication under a cellularcommunication protocol between UE 300 (such as DUE2 as shown in FIG. 1)and a second UE (such as DUE4 as shown in FIG. 1) from a first UE suchas DUE5 (served as a cluster head) as shown in FIG. 1.

The control unit 320 may modulate and code data to be transmitted basedon the MCS information.

Here, the communication unit 310 may transmit the modulated and codeddata to be transmitted to DUE4 by the resources, so as to perform theD2D communication.

As shown in FIG. 3, UE 300 may further include a measurement unit 330.The measurement unit 330 may measure quality of a link between UE 300(such as DUE2 as shown in FIG. 1) and DUE4. In addition, thecommunication unit 310 may transmit indication information on thequality of the link to DUE5 served as the cluster head.

According to the embodiment of the present disclosure, UE 300 (such asDUE2 as shown in FIG. 1) can perform D2D communication with a third UE(such as the source DUE as shown in FIG. 1) before performing the D2Dcommunication with DUE4. In this case, the measurement unit 330 maymeasure quality of a link between UE 300 (such as DUE2 as shown in FIG.2) and the source DUE. Furthermore, the communication unit 310 maytransmit indication information on the quality of the link to DUE5served as the cluster head.

According to the embodiment of the present disclosure, the communicationunit 310 may also receive, from DUE5 served as the cluster head, atleast one of measurement configuration information for measuring qualityof a link between UE 300 (such as DUE 2 as shown in FIG. 1) and DUE4;HARQ configuration information for the D2D communication between UE 300(such as DUE 2 as shown in FIG. 1) and DUE4; and D2D communicationconnection assistance information for accessing into DUE4.

According to the embodiment of the present disclosure, the communicationunit 310 may transmit a D2D RA preamble to DUE4 through D2D RACH basedon the assistance information, so as to access into DUE4, and mayreceive an access response from DUE4. Here, the access response mayinclude at least one of timing advance and scheduling arrangement fordata to be transmitted. In this example, a scheduler may be arranged inDUE4, and the scheduler performs resource scheduling for eachtransmission based on the resources and the MCS configured by thecluster head, for example, the scheduler in DUE4 may specify whichresource block will carry data to be transmitted in a case that theresources configured by the cluster head are several time-frequencyresource block.

According to the embodiment of the present disclosure, the communicationunit 310 may transmit acknowledge information indicating that the D2Dcommunication with DUE 4 has been established successfully to DUE5severed as the cluster head after receiving the access response, andstops receiving information from the source DUE.

According to the embodiment of the present disclosure, the communicationunit 310 may receive broadcasting information from the source DUEthrough a D2D broadcasting link, and transmit a transmission framenumber status for UE 300 (such as DUE2 shown in FIG. 1) and the sourceDUE to DUE 5 served as the cluster head. DUE 2 establishes unicastingD2D communication with DUE4 with the assistance of DUE5, and continuesto receive broadcasting information from DUE4. It should be noted that,DUE 2 does not transmit the transmission frame number status for thesource DUE to DUE5 in a case of no concerning the broadcastinginformation, and correspondingly, the cluster head DUE 5 does not notifythe target DUE 4 of information on the transmission frame number.

A communication switch process in a wireless communication systemaccording to an embodiment of the present disclosure is described belowin conjunction with FIG. 4 and FIG. 5. FIG. 4 shows a switch flow fromD2D broadcasting to D2D unicasting within a coverage scope of a basestation equipment according to an embodiment of the present disclosure,and FIG. 5 shows a switch flow from D2D broadcasting to D2D unicastingoutside of the coverage scope of the base station equipment according toan embodiment of the present disclosure.

In a scenario of switching from a D2D broadcasting communication mode toa D2D unicasting communication mode within a coverage scope of atraditional cellular network, a main flow is described as follows.

1. In a case that a DUE which is performing D2D broadcastingcommunication detects that quality of a broadcasting link of the DUEgets worse, the DUE notifies a cluster head (CH) of a message that thequality of the broadcasting link gets worse, and the cluster headtransmits measurement configuration information to the DUE and a newtarget DUE.

2. The DUE transmits a measurement report to the cluster head aftermeasuring by using the measurement configuration information, and thecluster head makes a decision on switching D2D communication mode basedon the measurement report, and transmits a switch request to an eNB(evolution Node Base Station).

3. The eNB allocates resources to the DUE and the new target DUE, andtransmits necessary information to the cluster head, to determine toswitch.

4. The cluster head transmits required configuration information to theDUE and the new target DUE, and assists the DUE in establishing D2Dunicasting communication with the new target DUE.

Specifically, as shown in FIG. 4, in step 1, the DUE transmitsinformation to the cluster head in a case of detecting that quality of aD2D broadcasting link gets worse.

In step 2, the cluster head transmits configuration information to theDUE to perform corresponding measurement, and the cluster headconfigures a new target DUE to transmit a reference signal to bemeasured by the DUE, the configuration information includes for examplephysical resource information for transmitting/receiving the referencesignal.

In step 3, the DUE performs the corresponding measurement and thentransmits a measurement report to the cluster head.

In step 4, the cluster head (CH) makes a switch decision based on themeasurement report transmitted by the DUE and wireless resourcemanagement within the cluster.

In step 5, the cluster head transmits a SWITCH REQUEST message to theeNB, the SWITCH REQUEST message carries necessary information forperforming the D2D unicasting communication by the DUE. The necessaryinformation may include for example, an ID of the DUE, an ID of the newtarget DUE and radio access bearer context (E-RAB context) which mainlyincludes necessary addressing information for a radio network layer(RNL) and a transmission network layer (TNL) and a Qos configurationfile of radio access bearer.

In step 6, the eNB performs access control. Specifically, the eNBdetermines whether resources required by communication can be ensuredbased on the Qos information of radio access bearer transmitted by theCH. Then, the eNB allocates resources dynamically based on the Qosrequirement. In addition, in a case that the new target DUE belongs toan adjacent cell, the eNB interacts with a service base station of thenew target DUE via an X2 interface, to discuss the issue of resourceallocation.

In step 7, the eNB prepares for switching and transmits a SWITCH REQUESTACKNOWLEDGE message to the CH, the SWITCH REQUEST ACKNOWLEDGE messagecarries information required by switching the D2D communication mode bythe DUE. The SWITCH REQUEST ACKNOWLEDGE message mainly includes resourceallocation assurance, a default D2D RACH preamble for establishing arandom connection between the DUE and the new target DUE and otherparameters such as an access parameter of D2D unicasting.

In step 8, the cluster head configures and then transmits configurationinformation to the DUE and the new target DUE. Specifically, the clusterhead may generate RRCConnectionReconfiguration message including amobilityControlInformation message. The RRCConnectionReconfigurationmessage mainly includes resource allocation, a modulation and codingscheme (MCS), a HARQ of D2D unicasting, an SN STATUS TRANSFER messagewhich is a frame number reception status transmitted to a PDCP layer ofthe new target DUE.

It should be noted that the HARQ is also supported in the D2Dbroadcasting communication in some examples, a time resource iscontacted by a HARQ entity, to perform blind integration on HARQtransmission (retransmission). Therefore, the HARQ is reconfigured in acase of switching the D2D communication from the broadcasting mode tothe unicasting mode, to meet a communication requirement.

In step 9, the DUE accesses into the new target DUE based on theRRCConnectionReconfiguration message (including themobilityControlInformation message) transmitted by the cluster head in away of D2D random access, and acquires synchronization from the DUE tothe new target DUE.

In step 10, the new target DUE transmits an access response to the DUE.The access response may include scheduling arrangement (SA) forindicating when, where and how the new target DUE transmits D2Dinformation to the DUE and timing advance (TA).

In step 11, the DUE transmits RRCConnectionReconfigurationCompletemessages to the CH and the new target DUE respectively aftersuccessfully accessing into the new target DUE, to confirm that the D2Dcommunication mode is switched. In this case, the new target DUE checksthe received RRCConnectionReconfigurationComplete message, and thentransmits data to the DUE.

In step 12, the DUE releases resources related the D2D broadcastingcommunication, and therefore, the switch flow is ended.

In another aspect, in a scenario of switching from a D2D broadcastingcommunication mode to a D2D unicasting communication mode outside of acoverage scope of a traditional cellular network, a main flow isdescribed as follows.

1. In a case that a DUE which is performing D2D broadcastingcommunication detects that quality of a broadcasting link of the DUEgets worse, the DUE notifies a cluster head (CH) of a message that thequality of the broadcasting link gets worse, and the cluster headtransmits measurement configuration information to the DUE and a newtarget DUE.

2. The CH makes a decision on switching the communication mode based ona measurement report of the DUE, and performs resource allocation on theDUE and the new target DUE in a resource pool based onpre-configuration.

3. The DUE realizes switch from the D2D broadcasting communication tounicasting communication with the new target DUE based on acquiredconfiguration information.

Specifically, as shown in FIG. 5, in step 1, the DUE transmitsinformation to the cluster head in a case of detecting that quality of aD2D broadcasting link gets worse.

In step 2, the cluster head performs measurement control. Specifically,the cluster head transmits configuration information to the DUE toperform a corresponding measurement. Furthermore, the cluster headconfigures a new target DUE to transmit a reference signal to bemeasured by the DUE.

In step 3, the DUE performs the corresponding measurement and transmitsa measurement report to the cluster head.

In step 4, the cluster head (CH) makes a switch decision based on themeasurement report transmitted by the DUE and wireless resourcemanagement within the cluster.

In step 5, the cluster head performs access control. Specifically, theCH determines whether resources required by the communication can beensured in a pre-configured resource pool based on received Qosinformation of radio bearer. Then, the CH allocates resources based onthe Qos requirement and the pre-configured resource pool.

In step 6, the cluster head configures the DUE and the new target DUE.Specifically, the cluster head generates RRCConnectionReconfigurationmessage including a mobilityControlInformation message. TheRRCConnectionReconfiguration message mainly includes resourceallocation, a modulation and coding scheme (MCS), HARQ of D2Dunicasting, an SN STATUS TRANSFER message which is a frame numberconnection status transmitted to a PDCP layer of the new target DUE.

It should be noted that the HARQ is also supported in the D2Dbroadcasting communication, a time resource is contacted by a HARQentity, to perform blind integration on HARQ transmission(retransmission). The HARQ is reconfigured in a case of switching theD2D communication from the broadcasting mode to the unicasting mode, tomeet a communication requirement.

In step 7, the DUE accesses into the new target DUE based on theRRCConnectionReconfiguration message (including themobilityControlInformation message) transmitted by the cluster head in away of D2D random access, and acquires synchronization from the DUE tothe new target DUE.

In step 8, the new target DUE transmits an access response to the DUE.The access response may include scheduling arrangement (SA) forindicating when, where and how the new target DUE transmits D2Dinformation to the DUE and timing advance (TA).

In step 9, the DUE transmits RRCConnectionReconfigurationCompletemessages to the CH and the new target DUE respectively aftersuccessfully accessing into the new target DUE, to confirm that the D2Dcommunication mode is switched. In this case, the new target DUE checksthe received RRCConnectionReconfigurationComplete message, and thentransmits data to the DUE.

In step 10, the DUE releases resources related the D2D broadcastingcommunication, and therefore, the switch flow is ended.

The scenario of switching from the D2D broadcasting communication modeto the D2D unicasting communication mode is described above. A scenarioof switching from a short-distance D2D communication mode to atraditional cellular communication mode is described below.

FIG. 6 shows a scenario of switching from a D2D communication mode to acellular communication mode. As shown in FIG. 6, a slave D2D user (aslave DUE) is in the D2D communication mode, and is in an LTE-DETACHstate. In a case that a whole cluster has a strong mobility (such as ina scenario of high-speed rail), signaling overhead is large in a casethat the slave DUE maintains a link with a base station. In a case thatthe slave DUE is in the LTE-DETACH state and only maintains a controllink with a cluster head, unnecessary signaling overhead can be omitted.

In the embodiment, the slave DUE refers to a UE within a short-distanceD2D communication cluster which does not maintain a cellular link with aservice base station of the slave DUE. The cluster head refers to a UEwithin the short-distance D2D communication cluster which maintains acellular link with the service base station of the cluster head. Inaddition, a target base station refers to a target base station to beconnected to the slave DUE in a switching process.

In a traditional switch flow without the assistance of the cluster headknown by the inventor of the present disclosure, the slave DUE will takea long time period to perform cell search and cell selection, andtherefore signaling overhead between the network and the UE is large.

In order to solve the problem in the traditional switch flow that thesignaling overhead between the network and the UE is large, anelectronic device on a UE side in a wireless communication system isprovided in the present disclosure, which can enhance an assisting roleof the cluster head, thereby reducing the signaling overhead between thenetwork and the slave DUE.

FIG. 7 shows a structure of a UE 800 according to another embodiment ofthe present disclosure. UE 800 may be served as a cluster head as shownin FIG. 6. As shown in FIG. 7, UE 800 may at least include a measurementunit 810 and a prediction unit 820.

The measurement unit 810 may measure a base station equipment includedin a potential cell list. A potential target cell of a slave DUE isstored in the potential cell list (PotentialCellList), the potentialcell list may include a source base station of the cluster head, a cellstored in the slave DUE, a cell stored in the cluster head and anadjacent cell.

The prediction unit 820 may predict, based on a measurement result ofthe measurement unit 810, a target base station equipment for the salveDUE in a UE cluster which performs D2D communication.

According to the embodiment of the present disclosure, since that theassisting role of the cluster head is enhanced, the signaling overheadbetween the network and the slave DUE can be reduced.

As shown in FIG. 7, UE 800 may further include a receiving unit 830 as afirst receiving unit. The receiving unit 830 may receive switch requestinformation indicating switching from a D2D communication mode to atraditional cellular communication mode from the slave DUE. The switchrequest information may include information on the potential cell list.

Furthermore, as shown in FIG. 7, UE 800 may further include atransmitting unit 840 as a first transmitting unit, a receiving unit 850as a second receiving unit and a transmitting unit 860 as a secondtransmitting unit.

The transmitting unit 840 may transmit random access preambleinformation to the target base station equipment.

Subsequently, the receiving unit 850 may receive random access responseinformation from the target base station equipment.

The transmitting unit 860 may transmit switch response information tothe slave DUE based on the random access response information.

According to the embodiment of the present disclosure, in a case thatthe random access response information indicates that access fails, theprediction unit 810 may predict a further target base station equipmentfrom the remaining base station equipments included in the potentialcell list, until access succeeds.

According to the embodiment of the present disclosure, in a case thatthe access fails for all of the base station equipments included in thepotential cell list, the transmitting unit 860 can transmit informationindicating performing traditional switching from the D2D communicationmode to the traditional cellular communication mode to the slave DUE.

According to the embodiment of the present disclosure, in a case thatthe random access response information still indicates that access failswhen a predetermined time elapses after the receiving unit 830 receivesthe switch request information, the transmitting unit 860 can transmitinformation indicating performing traditional switching from the D2Dcommunication mode to the traditional cellular communication mode to theslave DUE.

A communication switching process in a wireless communication systemaccording to another embodiment of the present disclosure is describedbelow in conjunction with FIG. 8. FIG. 8 shows a flow of switching froma D2D communication mode to a traditional cellular communication modewith the assistance of a cluster head according to another embodiment ofthe present disclosure.

In a scenario of switching from the D2D communication mode to thetraditional cellular communication mode with the assistance of thecluster head, a base flow is described as follows.

1. A slave DUE is connected to a target cell with the assistance of thecluster head, the cluster head can assist the slave DUE in rapidlyrealizing the switching by virtual random access.

2. In a case that random access is successful with the assistance of thecluster head, the cluster head can collect system information, andnotify the slave DUE that the slave DUE can be connected with a targetbase station based on the system information transmitted by the targetbase station.

3. In a case that the assistance of the cluster head is unsuccessfulrandomly before a switch assistance timer overflows or within a switchassistance threshold, the slave DUE will trigger a traditional switchingflow without the assistance of the cluster head.

Specifically, as shown in FIG. 8, in step 0, D2D communication similarto cellular communication is performed between the slave DUE and thecluster head, and the cluster head has a traditional cellularcommunication link with the base station.

In step 1, the slave DUE transmits a switch request to the cluster head,to indicate that the slave DUE is to switch from a D2D mode to acellular mode. Here, a switchAssitanceTimer is arranged in the salveDUE, to indicate an assistance time of the cluster head. In a case thatthe slave DUE does not receive a switch response from the cluster headbefore the timer overflows, the slave DUE will trigger the traditionalswitching. A cell information list is included in the switch requesttransmitted by the slave DUE, and wireless bearer information before theD2D communication is stored in the cell information list.

In step 2, the cluster head prepares for a switching flow. Specifically,the cluster head can predict an optimal target base station for theslave DUE based on measurement (from the potential cell list) of thebase station. The cluster head can manage switchAssistanceInformation,to store assistance information for the slave DUE. In addition, thecluster head can count the SwitchAssistanceThreshold. In a case that theSwitchAssistanceThreshold is equal to |PotentialCellList| (the number ofcells in the potential cell list), the cluster head fails to realizeassistance random access, and the cluster head will notify the salve DUEof starting a traditional switching flow.

In step 3, the cluster head transmits a RA Preamble to the target basestation.

In step 4, the target base station performs admission control.

In step 5, the target base station transmits a random access response(RA Response) to the cluster head. Specifically, the cluster headreceives the RA Response, and records uplink grand (UL Grant), timingadvance indication (timing advance indication) and temporary C-RNTI(temporary cell radio network temporary indication) in theswitchAssistanceInformation (switch assistance information).

In step 6, the cluster head transmits a switch response (switchresponse) to the slave DUE, the switch response includesswitchAssistanceInformation. The switch response includes for example ULGrant, Timing advance indication, cell information (for example PLMN(Public Land Mobile Network), a cell ID, a carrier frequency,traditional system information in MIB and SIB), temporary C-RNTI and soon.

In step 7, a RRC process is performed between the slave DUE and thetarget base station. Specifically, the salve DUE may transmit anRRCConnectionRequest (RRC connection request) to the target basestation. And the target base station transmits RRCConnectionSetup (RRCconnection setup) to the slave DUE. Then, the slave DUE can transmitRRCConnectionSetupComplete (RRC connection setup complete) to the targetbase station.

In step 8, the target base station transmits a signaling on UE contextrelease (UE context release) to the cluster head. Here, the target basestation notifies of the cluster head of successful switch. And thecluster head triggers releasing the resources.

In step 9, the cluster head releases the D2D resources, that is,wireless resources related to the slave DUE for mode switching, userdata plane resources and control data plane resources.

In step 10, the cluster head transmits switch request acknowledge(switch request acknowledge) to the slave DUE. At this time, the slaveDUE receives the switch request acknowledge, which indicates that theswitch is successful.

A wireless communication method in a wireless communication system isdescribed below. The wireless communication method includes: performingD2D communication under a cellular communication protocol with multipleUEs by an electronic device on a UE side in the wireless communicationsystem, to directly transmit data information and/or control informationto the multiple UEs; configuring, for a first UE and a second UE in themultiple UEs, resources and a MCS for performing the D2D communicationbetween the first UE and the second UE. The second UE is a candidateobject with which the first UE performs the D2D communication, andinformation indicating the resources and the MCS is transmitted to thefirst UE and the second UE.

Preferably, indication information indicating quality of a link betweenthe first UE and the second UE is received from the first UE. Theresources and the MCS for performing the D2D communication between thefirst UE and the second UE are configured in a case that the indicationinformation indicates that the quality of the link meets a predeterminedcondition.

Preferably, in a case that the electronic device is located within aservice scope of a base station equipment, switch request informationindicating that the first UE is to perform the D2D communication withthe second UE may be transmitted to the base station equipment, andswitch request acknowledge information is received from the base stationequipment. The switch request acknowledge information includes resourceallocation information for the D2D communication between the first UEand the second UE, and the configuration is at least based on the switchrequest acknowledge information.

Preferably, in a case that the electronic device is located outside ofthe service scope of the base station equipment, resources are selectedfrom a predetermined D2D communication resource pool to configure.

Preferably, indication information indicating quality of a link betweenthe first UE and a third UE is received from the first UE, and thepredetermined condition at least includes that the quality of the linkbetween the first UE and the second UE is better than the quality of thelink between the first UE and the third UE.

Preferably, information indicating that the third UE is a broadcastinginformation source for the first UE and the second UE may be receivedfrom the first UE and/or the second UE, it is determined that the firstUE performs unicasting D2D communication with the second UE in a casethat the present condition is met. A transmission frame number statusfor the first UE and the third UE may be received from the first UE, andthe transmission frame number status is transmitted to the second UE, sothat the first UE can continue to receive broadcasting information ofthe third UE from the second UE.

Preferably, HARQ for performing the D2D communication between the firstUE and the second UE may further configured, and HARQ configurationinformation is transmitted to the first UE and the second UE.

Preferably, D2D communication connection assistance information foraccessing into the second UE may be further configured for the first UE,and the D2D communication connection assistance information istransmitted to the first UE.

Preferably, the information indicating the resources and the MCS may betransmitted to the first UE and the second UE by a RRC signaling.

Another wireless communication method in a wireless communication systemis described below. The wireless communication method includes:receiving from a first UE, by an electronic device on a UE side in awireless communication system, information indicating resources and aMCS for performing D2D communication under a cellular communicationprotocol between the electronic device and a second UE; modulating andcoding data to be transmitted based on the MCS information; andtransmitting the modulated and coded data to be transmitted to thesecond UE via the resources to perform the D2D communication.

Preferably, the wireless communication method may include measuringquality of a link between the electronic device and the second UE, andtransmitting indication information on the quality of the link to thefirst UE.

Preferably, the electronic device can perform D2D communication with athird UE before performing D2D communication with the second UE, canmeasure quality of a link between the electronic device and the thirdUE, and transmitting indication information on the quality of the linkto the first UE.

Preferably, the electronic device may receive, from the first UE, atleast one of measurement configuration information for measuring thequality of the link between the electronic device and the second UE;HARQ configuration information for the D2D communication between theelectronic device and the second UE; and D2D communication connectionassistance information for accessing into the second UE.

Preferably, the electronic device may transmit the assistanceinformation to the second UE to access into the second UE, and receivean access response from the second UE. The access response may includeat least one of timing advance and scheduling arrangement for the datato be transmitted.

Preferably, the electronic device may transmit acknowledge informationindicating that the D2D communication with the second UE has beenestablished successfully to the first UE after receiving the accessresponse, and stop receiving information from the third UE.

Preferably, the electronic device may receive broadcasting informationfrom the third UE via a D2D broadcasting link, and transmit atransmission frame number status between the electronic device and thethird UE to the first UE, and establish unicasting D2D communicationwith the second UE with assistance of the first UE, and continue toreceive the broadcasting information from the second UE.

Another wireless communication method in a wireless communication systemis described below. The wireless communication method includes:measuring a base station equipment included in a potential cell list byan electronic device on a UE side in the wireless communication system;and predicting, based on a measurement result, a target base stationequipment for a UE in a UE cluster which performs D2D communication.

Preferably, the wireless communication method may further include:receiving from the UE, switch request information indicating switchingfrom a D2D communication mode to a traditional cellular communicationmode, the switch request information includes information on a potentialcell list.

Preferably, the wireless communication method may further include:transmitting random access preamble information to the target basestation equipment; receiving random access response information from thetarget base station equipment; and transmitting switch responseinformation to the UE based on the random access response information.

Preferably, in a case that the random access response informationindicates that the access fails to, a further target base stationequipment may be predicted from the remaining base station equipmentsincluded in the potential cell list, until the accesses succeeds.

Preferably, in a case that the access fails for all of base stationequipments included in the potential cell list, information indicatingperforming traditional switching from the D2D communication mode to thetraditional cellular communication mode is transmitted to the UE.

Preferably, in a case that the random access response information stillindicates that the access fails when a predetermined time elapses afterthe switch request information is received, information indicatingperforming traditional switching from the D2D communication mode to thetraditional cellular communication mode is transmitted to the UE.

Various implementation for various steps in the wireless communicationmethod in a wireless communication system according to the embodimentsof the present disclosure have been described in detail above, which arenot described repeatedly any more.

An electronic device is further provided according to an embodiment ofthe present disclosure, the electronic device includes a processingcircuit configured to: perform D2D communication under a cellularcommunication protocol with multiple UEs, to directly transmit datainformation and/or control information to the multiple UEs; configure,for a first UE and a second UE in the multiple UEs, resources and a MCSfor performing the D2D communication between the first UE and the secondUE. The second UE is a candidate object with which the first UE performsthe D2D communication, and information indicating the resources and theMCS is transmitted to the first UE and the second UE.

An electronic device is further provided according to an embodiment ofthe present disclosure, the electronic device includes a processingcircuit configured to: receive from a first UE, information indicatingresources and a MCS for performing D2D communication under a cellularcommunication protocol between the electronic device and a second UE;modulate and code data to be transmitted based on the MCS information;and transmitted the modulated and coded data to be transmitted to thesecond UE via the resources to perform the D2D communication.

An electronic device is further provided according to an embodiment ofthe present disclosure, the electronic device includes a processingcircuit configured to: measure a base station equipment included in apotential cell list; and predict, based on a measurement result, atarget base station equipment for a UE in a UE cluster which performsD2D communication.

It should be understood that the electronic device described above canalso perform other technical solution of the present disclosuredescribed above, which is not described here any more for simplicity.

Obviously, operation processes in the wireless communication method inthe wireless communication system according to the present disclosurecan be implemented by a computer-executable program stored in amachine-readable storage medium.

The objective of the present disclosure can be realized by a waydescribed as follows: a storage medium in which the computer-executableprogram code is stored is directly or indirectly provided to a system ora device, and a computer or a central processing unit (CPU) in thesystem or the device can read out and execute the program code describedabove. In this case, as long as the system or the device has a functionof executing the program, the embodiment of the present disclosure isnot limited to the program, and the program may be in any form, such asa target program, a program executed by an interpreter or a scriptprovided to an operating system or the like.

The machine-readable storage medium described above may include but notlimited to various storage or storage units, semi-conductor device, amagnetic disk unit such as an optical disk, a magnetic disk and amagnetic-optical disk, and other medium suitable for storinginformation.

In addition, the computer downloads and installs the computer programcode according to the present disclosure by being connected with awebsite on the Internet, and then executes the program code, to realizethe technical solution of the present disclosure.

FIG. 9 is a block diagram of exemplary structure of a general-purposepersonnel computer which can implement the wireless communication methodin the wireless communication system according to the embodiments of thepresent disclosure.

As shown in FIG. 9, CPU 1301 executes various processing based on aprogram stored in a random-only memory (ROM) 1302 or a program loadedinto the random access memory (RAM) 1303 from a storage part 1308. Datarequired when CPU 1301 executes various processing is stored in RAM 1303as needed. CPU 1301, ROM 1302 and RAM 1303 are connected with each othervia a bus 1304. An input/output interface 1305 is also connected withthe bus 1304.

The input/output interface 1305 is connected with an input part 1306(including a keyboard, a mouse and so on), an output part 1307(including a display such as a Cathode Ray Tube (CRT) and a LiquidCrystal Display (LCD), a loudspeaker and so on), a storage part 1308(including a hard disk), and a communication part 1309 (including anetwork interface card such as a LAN card, a modem and so on). Thecommunication part 1309 performs communication processing via a networksuch as the Internet. A driver 1310 may be connected with theinput/output interface 1305 as needed. A removable medium 1311 such as amagnetic disk, an optical disk, a magneto-optical disk and asemiconductor memory is installed in the driver 810 as needed, so that acomputer program read from the removable medium 1311 can be installed inthe storage part 1308 as needed.

In a case that the processing described above is implemented with thesoftware, a program composing the software is installed from a networksuch as the Internet or a storage medium such as the removable medium1311.

It should be understood by those skilled in the art that, the storagemedium is not limited to the removable medium 1311 shown in FIG. 9 inwhich the program is stored and which is distributed separately from thedevice to provide the program to the user. The removable medium 1311 maybe for example a magnetic disk (including a floppy disk (registeredtrademark)), an optical disk (including a Compact Disk Read-Only Memory(CD-ROM) and Digital Video Disk (DVD)), a magneto-optical disk(including minidisk (MD) (registered trademark)) and a semiconductormemory. Alternatively, the storage medium may be the ROM 1302, the harddisk included in the storage part 1308 or the like, in which the programis stored, and both the program and the device including the program aredistributed to the user.

As described above, the present disclosure provides the electronicdevice on the user equipment side in the wireless communication systemand the wireless communication method in the wireless communicationsystem, to enhance an assisting role of the cluster head.

According to design described above for the present disclosure, manyflows such as cell search, cell reselection, random access of the slaveDUE can be omitted, to reduce signaling overhead, and rapidly realizingswitch from the D2D mode to the traditional cellular mode.

In the system and method according to the present disclosure, obviously,components or steps can be decomposed or recombined. The decompositionor recombination are regarded as equivalent solutions of the presentdisclosure. Also, steps for implementing the processing described abovemay be performed in chronological order illustrated naturally, however,it is unnecessary to perform the steps in the chronological order. Somesteps can be performed in parallel or can be performed separately.

Although the embodiments of the present disclosure are described indetail above in conjunction with the drawings, it should be understoodthat the embodiments described above are only used to illustrate thepresent disclosure, and are not intended to limit the presentdisclosure. For those skilled in the art, various changes andalterations can be made to the embodiments described above withoutdeparting from the sprit and scope of the present disclosure. The scopeof the present disclosure is limited only by the appended claims and anequivalent concept thereof.

The invention claimed is:
 1. An electronic device on a user equipmentside in a wireless communication system, comprising: circuitryconfigured to perform device-to-device (D2D) communication under acellular communication protocol with a plurality of user equipments, totransmit data information and/or control information to the plurality ofuser equipments directly; receive indication information indicatingquality of a link between the first user equipment and the second userequipment from the first user equipment; receive indication informationindicating quality of a link between the first user equipment and athird user equipment from the first user equipment; determine whetherthe quality of the link between the first user equipment and the seconduser equipment is better than the quality of the link between the firstuser equipment and the third user equipment, in a case that it isdetermined that the quality of the link between the first user equipmentand the second user equipment is better than the quality of the linkbetween the first user equipment and the third user equipment,configure, for a first user equipment and a second user equipment of theplurality of user equipments, resources and a modulation and codingscheme (MCS) for performing the D2D communication between the first userequipment and the second user equipment, the second user equipment beinga candidate object with which the first user equipment performs the D2Dcommunication; and transmit information indicating the resources and theMCS to the first user equipment and the second user equipment.
 2. Theelectronic device according to claim 1, wherein the circuitry is furtherconfigured to transmit switch request information indicating that thefirst user equipment is to perform the D2D communication with the seconduser equipment to a base station equipment; receive switch requestacknowledgement information from the base station equipment, wherein theswitch request acknowledge information contains resource allocationinformation for the D2D communication between the first user equipmentand the second user equipment, and configure at least based on theswitch request acknowledgement information.
 3. The electronic deviceaccording to claim 1, wherein the circuitry is further configured toconfigure by selecting resources from a predetermined D2D communicationresource pool.
 4. An electronic device on a user equipment side in awireless communication system, comprising: circuitry configured toperform device-to-device (D2D) communication under a cellularcommunication protocol with a plurality of user equipments, to transmitdata information and/or control information to the plurality of userequipments directly; configure, for a first user equipment and a seconduser equipment of the plurality of user equipments, resources and amodulation and coding scheme (MCS) for performing the D2D communicationbetween the first user equipment and the second user equipment, thesecond user equipment being a candidate object with which the first userequipment performs the D2D communication: transmit informationindicating the resources and the MCS to the first user equipment and thesecond user equipment; and receive indication information indicatingquality of a link between the first user equipment and the second userequipment from the first user equipment, wherein in a case that thequality of the link indicated by the indication information meets apredetermined condition, the circuitry is further configured toconfigure the resources and the MCS for performing the D2D communicationbetween the first user equipment and the second user equipment, thecircuitry is further configured to receive indication informationindicating quality of a link between the first user equipment and athird user equipment from the first user equipment, and thepredetermined condition at least comprises that the quality of the linkbetween the first user equipment and the second user equipment is betterthan the quality of the link between the first user equipment and thethird user equipment, the circuitry is further configured to receiveinformation indicating that the third user equipment is a broadcastinginformation source for the first user equipment and the second userequipment from the first user equipment and/or the second userequipment, and in a case that the predetermined condition is met, thecircuitry is further configured to determine that the first userequipment performs unicasting D2D communication with the second userequipment, receive a transmission frame number status for the first userequipment and the third user equipment from the first user equipment,and transmit the transmission frame number status to the second userequipment, wherein the first user equipment continues to receivebroadcasting information of the third user equipment from the seconduser equipment.
 5. The electronic device according to claim 1, whereinthe circuitry is further configured to configure a hybrid automaticrepeat request HARQ for performing the D2D communication between thefirst user equipment and the second user equipment, and transmit HARQconfiguration information to the first user equipment and the seconduser equipment.
 6. The electronic device according to claim 1, whereinthe circuitry is further configured to configure, for the first userequipment, D2D communication connection assistance information foraccessing into the second user equipment, and transmit the D2Dcommunication connection assistance information to the first userequipment.
 7. The electronic device according to claim 1, wherein thecircuitry is configured to transmit the information indicating theresources and the MCS to the first user equipment and the second userequipment through an RRC (Radio Resource Control) signaling.
 8. Anelectronic device on a user equipment side in a wireless communicationsystem, comprising: circuitry configured to measure quality of a linkbetween the electronic device and a second user equipment; transmitindication information on the quality of the link between the electronicdevice and the second user equipment to a first user equipment; measurequality of a link between the electronic device and a third userequipment; transmit indication information on the quality of the linkbetween the electronic device and the third user equipment to the firstuser equipment; receive, from the first user equipment, informationindicating resources and a modulation and coding scheme MCS forperforming Device-to-Device (D2D) communication under a cellularcommunication protocol between the electronic device and the second userequipment, in a case that it is determined by the first user equipmentthat the quality of the link between the electronic device and thesecond user equipment is better than the quality of the link between theelectronic device and the third user equipment; modulate and code datato be transmitted based on the information indicating the resources andthe MCS; and transmit the modulated and coded data to be transmitted tothe second user equipment through the resources, to perform the D2Dcommunication.
 9. The electronic device according to claim 8, whereinthe circuitry is further configured to receive, from the first userequipment, at least one of measurement configuration information formeasuring quality of the link between the electronic device and thesecond user equipment, Hybrid Automatic Repeat Request (HARQconfiguration information for the D2D communication between theelectronic device and the second user equipment, and D2D communicationconnection assistance information for accessing into the second userequipment.
 10. An electronic device on a user equipment side in awireless communication system, comprising: circuitry configured toreceive, from a first user equipment, information indicating resourcesand a modulation and coding scheme MCS for performing Device-to-Device(D2D) communication under a cellular communication protocol between theelectronic device and a second user equipment; modulate and code data tobe transmitted based on the information indicating the resources and theMCS; transmit the modulated and coded data to be transmitted to thesecond user equipment through the resources, to perform the D2Dcommunication; measure quality of a link between the electronic deviceand the second user equipment; transmit indication information on thequality of the link between the electronic device and the second userequipment to the first user equipment; perform D2D communication with athird user equipment before performing the D2D communication with thesecond user equipment; measure quality of a link between the electronicdevice and the third user equipment; transmit indication information onthe quality of the link between the electronic device and the third userequipment to the first user equipment; receive, from the first userequipment, at least one of measurement configuration information formeasuring quality of the link between the electronic device and thesecond user equipment, Hybrid Automatic Repeat Request HARQconfiguration information for the D2D communication between theelectronic device and the second user equipment and D2D communicationconnection assistance information for accessing into the second userequipment; transmit the D2D communication connection assistanceinformation to the second user equipment, to access into the second userequipment; receive, from the second user equipment, an access responsecontaining at least one of timing advance and scheduling arrangement fordata to be transmitted; and after receiving the access response,transmit acknowledgement information indicating that D2D communicationwith the second user equipment has been established successfully to thefirst user equipment, and stop receiving information from the third userequipment.